HNO3 has three main chemical properties: acidic, nitrating, and oxidizing. As an acid, it donates one H+ ion and neutralizes bases. Its nitrating property allows it to add nitro groups to organic compounds like benzene. As a strong oxidizer, HNO3's nitrogen changes oxidation states and can oxidize metals and nonmetals, reducing itself to NO2, NO or N2O depending on conditions like concentration and reactivity of the substance. Its importance lies in uses like fertilizers, explosives, and dynamite where its acidity, nitrating, or oxidizing abilities are exploited.

1. Chemical Properties of HNO3
XII CHEMISTRY
Sidra Javed

2. Chemical properties of
HNO3 are of 3 types
1. Acidic properties
2. Nitrating properties
3. Oxidizing properties

3. Acidic properties of HNO3
● HNO3 is a strong monobasic/monoprotic acid i.e. provide
only 1 H+ ion
HNO3 + H2O → H3O+ + NO3
-
● Neutralizes alkalis/bases to give salt and water
HNO3 + NaOH → NaNO3 + H2O

4. Nitrating properties of HNO3
● HNO3 is a good nitrating agent
● When HNO3 vapors are passed through Methane at 450oC in presence
of copper, nitromethane is formed.
CH4 + HNO3 CH3NO2 + H2OCu
450oC

5. Nitrating properties of HNO3:
● Nitration of Benzene in presence of H2SO4:

6. Oxidising properties of HNO3:
● HNO3 is a strong oxidising agent
● Oxidation State of N changes from N+5 to N-3
● Degree of oxidation depends upon:
○ Concentration of acid
■ Lower concentration of acid → Greater oxidation
○ Nature of element
■ Highly reactive element → Greater oxidation

7. Reaction with Cu metal
● Concentrated HNO3 reduces to NO2
Cu + 4HNO3 (conc) → Cu(NO3)2 + 2NO2 + 2H2O

8. Reaction with Cu metal
● Dilute HNO3 reduces to NO
3Cu + 8HNO3 (dil) → 3Cu(NO3)2 + 2NO + 4H2O

9. Reaction with Mg (more
reactive metal)
● Dilute HNO3 reduces to N2O
4Mg + 10HNO3 → 4Mg(NO3)2 + N2O +
5H2O

10. Reaction with Zn (More
reactive metal)
● Very dilute HNO3 reduces to NH4NO3
4Zn + 10HNO3 → 4Zn(NO3)2 + NH4NO3 + 3H2O

11. Reactions with Nonmetals
● HNO3 oxidizes nonmetals and reduces to NO2
S + 6HNO3 → H2SO4 + 6NO2 + 2H2O
P + 5HNO3 → H3PO4 + 5NO2 + H2O
Si + 4HNO3 → SiO2 + 4NO2 + 2H2O

12. Importance & Uses
of HNO3

13. Fertilizers
NH4NO3 , NaNO3 etc

14. Explosives
Nitro glycerine

15. Explosives
Dynamite